Enantioselective Reductive Amination Research Articles

Enantioselective Reductive Amination of α-Keto Acids to α-Amino Acids by a Pyridoxamine Cofactor in a Protein Cavity

Adipocyte lipid binding protein (ALBP) is a small 131 residue protein with a simple architecture that consists of two orthogonal planes of β-sheet secondary structure. This protein binds a variety of fatty acids in a large cavity formed between the two sheets such that the bound ligands are completely enclosed within the protein. In this paper, the synthesis of an ALBP conjugate (ALBP-PX) containing a pyridoxamine cofactor attached to a thiol within the protein interior is described. The conjugate was characterized by mass spectrometry, UV/vis spectroscopy, and gel filtration chromatography. ALBP-PX reductively aminates a number of alkyl, aryl, and side chain functionalized α-keto acids to α-amino acids with enantioselectivities as high as 94% ee.